150 THE FLUIDS. 



the fact that it is required for the development of the cytoid cor- 

 puscles. 



2. The histological elements of the chyle are 1. Extremely minute 

 granules; 2. Coarse granules; 3. Distinct nuclei with nucleoli ; and 

 4. Cytoid corpuscles. It is only during digestion, however, that 

 these elements appear in a marked degree. 



1. The granules cover the field of view like a minute veil. They 

 constitute what Mr. Gulliver termed the molecular base of the chyle. 

 Mu'ller found them to be fat-granules surrounded by a proteine-like 

 (albuminous?) substance. Probably no true fat- globules normally 

 exist in the chyle. To this molecular base of the chyle its turbidity 

 and milky appearance are due. It is more abundant in proportion 

 as the food contains more fat. 



2. The coarse granules are grouped together, and appear to be 

 held in contact by a hyaline substance. (Mutter.) 



3. The nuclei are sharply defined, contain nucleoli, and are some- 

 times covered with individual granules. (Kottiker.) 



4. The cytoid corpuscles are identical with those of lymph (p. 148). 

 It is, however, an interesting fact, that, while they are often 3^5^ of 

 an inch in diameter in the lacteals, they are seldom more than ^-Q-Q 

 to 3^011 i n tae thoracic duct. 



Colored blood-corpuscles are also always found in the chyle from 

 the thoracic duct, these being either developed there from the cytoid 

 corpuscles, or being derived from the lymphatics of the spleen, as 

 already explained (p. 147). 



The quantity of the chyle entering the blood in twenty-four 

 hours is not satisfactorily settled. Yierordt estimates it at 5J 

 pounds ; Bidder at 6.6 pounds, as already stated (p. 148). 



Origin. Bernard concludes that chyle is formed by the digestion 

 of the fat alone in the food. If this be true, chyle is scarcely other- 

 wise than mere lymph, with an addition of fat. It is, however, very 

 certain that not all the fat in the food is converted into chyle and 

 absorbed by the lacteals, since the blood of the vena portas is almost 

 twice as rich in fat during the process of digestion as during fast- 

 ing. And, on the other hand, it is probable that the other elements 

 of food, besides fat, are not entirely excluded from absorption by 

 the lacteals, since the albuminous matters of the chyle are more 

 likely to have been admitted with the fat than to have been deve- 

 loped from the latter by the addition of nitrogen from the blood in 

 the mesenteric glands, as has been suggested. Since, however, the 



